Sound distributing panel and baffle for radio loudspeakers



Feb. 16, 1937.

w. J. MAXWELL 2,071,170

SOUND DISTRIBUTING PANEL AND BAFFLE FOR RADIO LOUDSPEAKERS Filed Dec. 14, 1935 INVENTOR M llldm J Maxwell ATTO R N EY Patented at. 16, 1937 PATENT OFFICE SOUND DISTRIBUTING PANEL AND BAFFLE FOB RADIO LOUDSPEAKERS William J. Maxwell, New York, N. Y. Application December 14, 1935, Serial No. 54,406

16 Claims.

This invention relates to new and useful improvements in a.sound propagating, mixing, regulating and distributing sound board, panel, baf-. fle, or other appliance, suitable for increasin regulating modifying, amplifying or improving the tones and other qualities of radio vibrations or sounds which are transmitted in, through or over loud speakers.

One of the means or methods for creating such an improvement and enabling such sounds or waves to be improved in tone, quality, resonance, volume, or to be modified and'regulated, is the construction of a sound board, panel, baiile, or other appliance, constructed of various thicknesses, and tapering gradually from a central thick area to the edges thereof, and an arrangement where theradio or the loud speaker or other substitute for a loud speaker, or for any other'appliance having the same or a similar 0 2 thick portion of the sound board, panel baille, or other appliance, so that the sounds therefrom are propagated, regulated, controlled, modified, amplified, distributed, produced or reproduced into good quality tones, and where undertones of different musical instruments or other instruments producing the sound are heard or better heard than they would be without the-use of the apparatus or invention herein described.

Still further, another one of the means or methods to be used, contemplates as a part of the invention, the provision of a tone pin mounted upon a cabinet or other receptacle or container in which a radio is used or contained, engaging against-the thick portion of the sound board, panel, bailie, or other appliance, to hold the same under tension, and to produce pressure on the tone pin, to increase or. having a tendency to .increase its vibrating quality and its resonance, or to increase, multiply, propagate or improve the vibrations or theresonance resulting therefrom.

Another object of the invention, covering one of the means of obtaining the beneficial results 45 above herein set forth, is'the construction of a device, .appliance or apparatus, as mentioned above, which is simple and durable, and which is capable of being manufactured and sold at a reasonable cost.

- I'br further comprehension of the invention, and of the objects-and advantages thereof, reference will be had to the followingdescription and accompanying drawing, and to the appended claims in which the various novel features of 6 theinvention. are more particularly set forth.

function, is associated with or attached upon the In the accompanying drawing forming a material part of this disclosure:-

Flg.,1 is a front elevational view of a device constructed according to this invention.

Fig. 2 is a sectional view taken on the linei-I 5 of Fig. 1.

Fig. 3 is a fragmentary enlarged detailed view of a portion of Fig. 2.

Fig. 4 is anelevational view looking in the direction of the line 4-4 of Fig. 3.

Fig. 5 is a vertical sectional view of another radio cabinet or container with a sound distributing, sound propagating, sound intensifying, sound regulating, sound amplifying, sound modifying, or sound controlling sound board, panel, baffle, or other appliance, according to a modification of the invention.

Fig. 6 is a fragmentary plan view looking in the direction of the line 6-8 of Fig. 5.

Fig. 7 is a plan view of .a combination support and tone pin which may be substituted for the corresponding parts shown in Figs. 5 and 6.

Fig. 8 is another vertical sectional view of a radio cabinet with a distributing panel and baffie according to a modification of the invention.

In the form of the invention illustrated in Figs. 1-4 inclusive there is a cabinet ill, for a radio, which is provided with a panel I I mounted on the front thereof and constructed according to this invention.

This panel has an intermediate thick portion II, and atapering portion II". The panel is under tension by reason of a tone pin II as hereinafter further described. For this latter reason, all portions of the panel are not in a common plane, but portions to different sides of the tone pin are disposed in different planes. Preferably, the panel is made of balsa wood and is' so designed that certain areas thereof have natural frequencies of vibration at certain pre- 40 determined rates. A preferred design would be one in which the portion A of the panel has a variable frequency of natural vibration and is adapted to support the loud speaker of the radio.

At the area indicate by the transverse line B, the panel may be d ed to have a frequency of 5,000 or more vibrations per second. At the area 0 the panel may be designed to have a frequency of 3,000 vibrations per second; at the area D, 1,500 vibrations per second; at the area E, 50 or less vibrations per second.

The tone pin I2 is supported or fixed upon a rigid transverse support I; mounted between the side walls of the cabinet. This tone pin engages against a small reinforcement H which is ata wooden button l6 disposed on the outside of' the panel I I. This adjustment screw has a bracket l1 swivelly mounted on its inner end. A tension spring [8 or other resilient member connects with this bracket and with another bracketi 9 swivelly mounted upon a rod which engages through the rigid support l3. The rod 20 has a head 20 upon its outer end which normally engages against the outer side of the support I 3.

'I'he spring [8 serves to resiliently hold the panel against the tone pin. The resiliency may be of a pre-determined amount or may be changed by screwing in or screwing out the screw l5 to various distances.

A further change of resiliency is possible by the provision of a wedge-shaped member 2| adjustably mounted on the outer face ofthe support l3. This wedge-shaped member is of step formation and is slidable between a pair of tracks 22. It is adapted to frictionally maintain various positions into which it is placed along the tracks. A stop 23 prevents its complete disengagement from the bottom ends of the tracks. The member 2! is formed with a slot 2 l adapted to accommodate the rod 20. The arrangement is such that the rod 20 may be manually drawn outwards to any desired degree and the member 2| moved-beneath the rod so that when the rod is released the head of the rod engages a selected step of the member. Thus, more or less tension may be placed upon the spring 18 in addition to the limits of adjustment of the screw IS.

The radio cabinet l0 has a shelf 24 near the top portion thereof upon which the chassis of through which the controls, such as the knobs of the radio set, may pass. These openings may be H decorated by veneered pieces 26 mounted upon the panel to surround the openings.

The panel ll may be made from one piece of material or from many pieces of material. As shown on the drawing, it is made from two pieces joined atthe center of the cabinet l0 along the line H. Small reinforcement joining strips 21 are glued or cemented upon the adjacent edges of the panel sections to join them together in a unit.

1 A loud speaker 28 for the radio is -*mounted upon the portion A of the panel II. The speaker is cushioned with felt or rubber against the panel so,as not to transmit foreign vibrations to the panel. The speaker 28 has a flange or rim of speaker portion 28 upon which there is mounted a cushion gasket 29 of felt or rubber which is opening 30. A grille 3| is'supported upon the outside of the panel around theopening 30. This grille is .held spaced from the panel by several cushion washers 32. Bolts 33 engage through the grille I3, the'washer l2, and gasket 29, and the flange or rim of speaker 28 to support the grille and the loud speaker upon the panel to keep the speaker and grillein "floating condition. The panel H may constitute the, outer wall of the radio cabinet or any desired cabinet may be used, for example, one in which there are outer walls. In such cases the panel II is disposed within the cabinet and merely acts as a sound distributing panel and baiile for the radio loud speaker. n this case no grille is necessary and cushioning washers should be placed under the screw heads. o

In Figs. 5 and 6 a modifiediorm of the invention is disclosed which has specific reference to the tone pin. In this form of the invention there is a rigid support i3 mounted between the walls of the cabinet 10 but set in from the rear of the cabinet; in fact, the support I3 is located immediately adjacent the front of the cabinet. On this support I 3* there is a tone pin H in the form of a thin strip of wood which is rigidly attached-upon the support I 3' and bears against the panel li In other respects this form of the invention is identical to the previous form.

In Fig. 7 another modified form is shown in which there is a rigid support l3 fromthe sides of which a tone pin i2 projects. This tone pin is integral and is formed of small size at the front end and gradually tapers along the sides to the back end. 7

In Fig. 8 another modified fofin oi the invention is disclosed in which a cabinet III is illustrated provided with a panel li This panel is of similar design as the previous panels and should be provided with a tone pin and resilient member (not shown in this figure) as previously described. The feature of this form of the' invention relates to the mounting of the loud speaker. There is a transverserigid support. 35 mounted between the side walls of the cabinet Ill. The field 38 of the loud speaker of the radio is mounted upon a rod or support 31 which is attached upon the support 35. The coil 38 of the loud speaker is mounted upon the panel li field is maintained stationary, while the voice coil '38 is capable of vibrating, and correspondingly vibrates the panel.

Wherever the terrn "panel is used in describing the various novel features '0! the invention,

it shall be taken to include and mean in addition to its own meaning, any sound board, bafile, or

other mechanical appliance to be used for a similar purpose and constructed out of wood of any kind, metal, or of any other composition or matter. 1

While I have illustrated and described the preferred embodiment of my invention, it is to be understood that I do not limit myself to the precise construction herein disclosed and the right is reversed to all changesand modifications coming within the scope of the invention as defined in the appended claims.

Having thus described my invention, what I claim as new, and desire to secure by United States Letters Patent is:

1. A sound distributing panel and battle for loud speakers, comprising a cabinet, a panel mounted thereon and} constructed of varying thickness, a tone pin mounted on said cabinet and engaging said panelror holding it under tension, means for urging the panel against said tonepin, and a loud speaker mounted on said panel,

2. A sound distributing panel and battle for loud speakers, comprising a cabinet, 9. panel mounted thereon and constructed oi varying thickness, a

said panel for holding it under tension, means to urging the panel against said tone pin, and a loud speaker mounted on said panel, saidpa'nel and toge pin being resiliently associated with each er.

3. A sound distributing panel and baiile for loud speakers, comprising a cabinet, a panel mounted thereon and constructed of varying thickness, a tone pin mounted on said cabinet and en a in said panel for holding it under tension, means for urging the panel against said tone pin, and a loud speaker mounted on said panel. Said means for urging the panel against the tone pin including a resilient element.

;4. A sound distributing panel and baille for loud speakers, comprising a cabinet, a panel mounted thereon and constructed oi varying thickness, a

tone pin mounted on said cabinet and engaging said panel for holding it under tension, means for urging the panel against said tone pin, and

a loudspeaker mounted on said panel, said means for urging the panel against the tone pin including a resilient element, supported between the panel and a rigid support mounted upon the cabinet.

' 5. A sound distributing panel and baine for loud speakers, comprising a cabinet, a panel mounted thereon and constructed of varying thickness, a

' tone pin mounted on said cabinet and engaging said panel for holding it under tension, means for urging the panel against said tone pin, and a loud I speaker mounted on said panel, said means for urging the panel against the tone pin including a resilient element, supported between the panel and a rigid support mounted upon the cabinet, one end oi said spring being mounted upon a bracketswivelly over a screw adjustably mounted on the panel.

6, A sound distributing panel and baflie for loud speakers, comprising a cabinet, a panel mounted thereon and constructed of varying thickness, a

tone pin mounted on said cabinet and engaging said panel for holding it under tension, means for urging the panel against said tone pin, and a loud speaker mounted on said panel, said means for vurging the panel against the tone pin including a resilient element, supported between the panel and a rigid support mounted upon the cabinet, one end or said spring being mounted upon a bracket swivelly over a screw adjustably mounted on the panel, and the other end of the spring being mounted upon abracket swivelled on a rod extending through said support. g

7. A sound distributing panel and bai'lie {or loud speakers, comprising a cabinet, a pane mounted thereon and constructed oi. varying thickness, a

tone pin mounted on said cabinet and engaging said panel for holding it under tension, means for urging the panel against said tone pin, and

, a loud speaker mounted on said panel, said means for urging the panel against the tone pin including a resilient element, supported between the panel and a rigid support mounted upon the cabinet, one end of said spring being mounted upon a bracket swivelly over a screw adjustably mount ed on the panel, and the other end oi the sprin extending through said support, and .a wedgeshaped member adiustably mounted on said rigid support and holding said rod in various positions to supplement the adjustment of the resilient action of the spring.

8. A sound distributing panel and bailie for loud speakers, comprising a cabinet, a panel mountedthereon and constructed of varying thickness.-a tone pin mounted on said cabinet mounted thereon and constructed of varying thickness, a tone pin mounted on said cabinet and engaging said panel for holding it under tension, means for ,urging the panel against said tone pin, and a loud speaker mounted on said panel, said panel being designed so that ditlerent portions thereof are adapted to vibrate at predetermined natural frequencies.

10. A sound distributing panel and baille for loud speakers, comprising a cabinet, 9. panel mounted thereon and constructed of varying thickness, a tone 'pin mounted on said cabinet and engaging said panel for holding it under tension, means for urging the panel against said tone pin, and a loud speaker mounted on said panel, said tone pin comprising a rod supported upon a rigid support mounted on said cabinet, and the front end of said rod engaging against a strip secured upon the rear face of the panel.

11. A sound distributing panel and bafile for loud speakers, comprising a cabinet, a panel mounted thereon and constructed of varying thickness, a tone pin mounted on said. cabinet and engaging said panel for holding it under tension, means for urging the panel against said tone pin, and a loud speaker mounted on said panel, said tone pin comprising a strip engaging against the panel and mounted on a support member which is in turn mounted upon said cabpanel, the field oi the loud speaker being supported from the cabinet, and the coil' of the loud speaker being mounted on said panel.

13. A sound distributing panel and baiile for loud speakers, comprising a cabinet, a panel mounted thereon and constructed oivarying thickness, a tone pin mounted on said cabinet and engaging said panel for holding it under tension, means for urging the panel against said tone pin, and a loud speaker mounted on said panel, said panel being of balsa wood.

14. A sound distributing panel and baflie for loud speakers, comprising a cabinet, a panel mounted thereon and constructed of varying thickness, a tone pin mounted on said cabinet and engaging said panel for holding it under tension, means for urging the panel against said tone pin, and-aloud speaker mounted on said panel, said panel being of balsa wood, and the loud speaker being spaced by a cushioning member from the said panel.

15. A sound distributing panel and baiile for loud speakers, comprising a cabinet; a panel mounted thereon and constructed of varying thickness, a tone pin mounted on said cabinet and engaging said panel for holding it under tenboth the grille and the loud speakerbeing, spacem 4 2,071,170 by a cushioning member from the said panel to and engaging said panel for holding it under tenkeep the grille and the loud speaker in cushsion, means for urging the panel against said ioned or floating condition. tone pin, a sound insulated grill-e and a sound 16. Asound distributing panel and baflle of balsa insulated loud speaker mounted on said panel,

wood for loud speakers, comprising a cabinet, 9. said grille being in juxtaposition with said loud 5 panel mounted thereon and constructed of varyspeaker. ing thickness, a tone pin mounted on said cabinet WILLIAM J. MAXWELL. 

